Optimal Timing of Surgical Revascularization for Myocardial Infarction and Left Ventricular Dysfunction / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The optimal timing of surgical revascularization for patients presenting with ST-segment elevation myocardial infarction (STEMI) and impaired left ventricular function is not well established. This study aimed to examine the timing of surgical revascularization after STEMI in patients with ischemic heart disease and left ventricular dysfunction (LVD) by comparing early and late results.</p><p><b>METHODS</b>From January 2003 to December 2013, there were 2276 patients undergoing isolated coronary artery bypass grafting (CABG) in our institution. Two hundred and sixty-four (223 male, 41 females) patients with a history of STEMI and LVD were divided into early revascularization (ER, <3 weeks), mid-term revascularization (MR, 3 weeks to 3 months), and late revascularization (LR, >3 months) groups according to the time interval from STEMI to CABG. Mortality and complication rates were compared among the groups by Fisher's exact test. Cox regression analyses were performed to examine the effect of the time interval of surgery on long-term survival.</p><p><b>RESULTS</b>No significant differences in 30-day mortality, long-term survival, freedom from all-cause death, and rehospitalization for heart failure existed among the groups (P > 0.05). More patients in the ER group (12.90%) had low cardiac output syndrome than those in the MR (2.89%) and LR (3.05%) groups (P = 0.035). The mean follow-up times were 46.72 ± 30.65, 48.70 ± 32.74, and 43.75 ± 32.43 months, respectively (P = 0.716). Cox regression analyses showed a severe preoperative condition (odds ratio = 7.13, 95% confidence interval 2.05-24.74, P = 0.002) rather than the time interval of CABG (P > 0.05) after myocardial infarction was a risk factor of long-term survival.</p><p><b>CONCLUSIONS</b>Surgical revascularization for patients with STEMI and LVD can be performed at different times after STEMI with comparable operative mortality and long-term survival. However, ER (<3 weeks) has a higher incidence of postoperative low cardiac output syndrome. A severe preoperative condition rather than the time interval of CABG after STEMI is a risk factor of long-term survival.</p>

Surgical ventricular restoration versus isolated coronary artery bypass grafting for left ventricular aneurysm: comparison of mid- to long-term outcomes / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the mid- to long-term outcomes of patients receiving isolated coronary artery bypass grafting (CABG) versus surgical ventricular restoration (SVR) plus CABG for left ventricular aneurysms.</p><p><b>METHODS</b>The clinical data were retrospectively analyzed in 205 patients with left ventricular aneurysms admitted to our hospital between January, 1997 and December, 2012, including 115 patients receiving SVR plus CABG and 90 undergoing isolated CABG. By matching preoperative echocardiographic parameters including aneurysm size, left ventricular ejection fraction (LVEF), left ventricular end-systolic volume index (LVESVI) and EuroSCORE risk factors, 32 patients receiving SVR plus CABG and another 32 with isolated CABG were enrolled in this study. The patients were compared for survival rates, major adverse cardiac or cerebrovascular events (MACCEs), left ventricular geometry and function at 1, 3 and 5 years of follow-up.</p><p><b>RESULTS</b>Compared with the patients receiving isolated CABG, those receiving SVR and CABG showed greater improvements in echocardiographic parameters and NYHA functional class. The differences in the echocardiographic parameters between the two groups gradually reduced with time and became comparable at 5 years after the operation (P>0.05). No significant difference was found in the mid- to long-term survival or the incidence of MACCEs between the two groups (P>0.05).</p><p><b>CONCLUSION</b>Compared with isolated CABG, SVR plus CABG does not reduce the incidence of MACCEs or improve the mid- to long-term survival rate of patients with left ventricular aneurysm with a LVESVI <60 mL/m(2).</p>

Different approaches to revascularization for complex coronary artery disease and left ventricular dysfunction: analysis of perioperative outcomes / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the perioperative outcomes of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) for treatment of complex coronary artery disease and left ventricular dysfunction.</p><p><b>METHDOS</b>The clinical data of 966 patients admitted to our hospital from January 2003 to December 2013 with coronary artery disease and left ventricular dysfunction (ejection fraction ≤50%) were retrospectively reviewed. Among the patients, 386 underwent CABG and 580 received PCI. After matching for EuroSCORE risk factors and preoperative echocardiographic parameters, 135 patients with CABG and 135 with PCI were enrolled in this study. With hospital mortality and perioperative major complications as the endpoints, the early outcomes of the procedures were evaluated. Perioperative echocardiography was performed to evaluate the change of left ventricular geometry and function.</p><p><b>RESULTS</b>Compared with CABG group, PCI group had significantly higher incidences of chronic lung disease (8.1% vs 0.7%, P=0.003) and recent myocardial infarction (64.4% vs 31.9%, P=0.000) but significantly lower left-main disease (12.6% vs 23.7%, P=0.018); the other baseline characteristics were comparable between the two groups. Patients with CABG had a greater number of treated target vessels than those with PCI (2.90±0.81 vs 1.67±0.73, P=0.000), and complete revascularization was more common in CABG group (94.8% vs 51.8%, P=0.000). No significant difference was found in perioperative variations of LVEF between the two groups, but patients with CABG had a greater variation in LVEDD than those with PCI. The hospital mortality and other major complications were similar between the two groups.</p><p><b>CONCLUSION</b>Both CABG and PCI are safe and reliable revascularization strategies for complex coronary artery disease and left ventricular dysfunction, but CABG can achieve a higher rate of complete revascularization and better improves the left ventricular function.</p>

Biodegradable polydioxanone mesh: Preparation, optimization and in vivo degradation / 第二军医大学学报

Objective: To prepare a novel surgery mesh made of polydioxanone(PDO) and to study its in vivo degradation properties and the related tissue reaction, so as to provide reference for future clinical application. Methods: PDO mesh was plain-woven and was coated with collagen and chitosan, then they were implanted into the dorsal muscle of rabbits for 2, 4, 8, 12, 16, and 24 weeks. Rabbits implanted with pure PDO mesh served as control. The degradation process of implanted materials, tissue-material interface, and the biological influence of the coating on the mesh were observed; tissue reaction was observed and evaluated by histological means and TEM. Results: Implantation of pure PDO mesh resulted in mild inflammation and fibrous tissues infiltrated into the mesh; degradation occurred during the 8th to the 12th week and degraded completely within 24 weeks; there was no denaturalization, necrosis, and abnormal hyperplasia in the surrounding tissues. Collagen coating stimulated a fibroblastic proliferation and was reabsorbed within 4 weeks; and the naked mesh was infiltrated by fibrous tissues. The chitosan coating showed a strong inhibitory effect on the growth of the surrounding connective tissues. Conclusion: The biodegradable polydioxanone mesh has an excellent biocompatibility, a friendly tissue-material interface and a proper degradation rate matching to the tissue regeneration rate. The biological characteristics of the mesh can be modified by different coatings, making it a very promising degradable surgical mesh.

A comparison of 2 kinds of hydroxyapatite/collagen composites as tissue engineering scaffold / 第二军医大学学报

Objective: To prepare 2 composites using different proportions of hydroxyapatite and collagen and to assess their structural and biological properties, so as to pave a way for preparing tissue engineering chest wall scaffold. Methods: Two kinds of hydroxyapatite/collagen composites were prepared according to the weight ratios of 1:1 and 1:2; collagen sponge served as control. Then the structures of the 2 composites and the collagen sponge were observed under SEM. In vivo study was conducted to assess the biocompatibility and biodegradation of the composites by gross inspection and histological examination. Results: The collagen sponge had a 3-D network structure with fluey collagen fibers and poor mechanical strength, and its structure was damaged within 2 weeks after implantation and was completely absorbed 4 weeks later. The hydroxyapatite and collagen were well mixed in the composite with a hydroxyapatite to collagen ratio of 1:2; the composite had homogeneous 3-D porous structure (size of the pore being 100-400 m) and showed good biocompatibility: maintained its porous structure 4 weeks after implantation and was absorbed within 8 weeks. In composite with hydroxyapatite to collagen ratio of 1:1, the hydroxyapatite particles were separated from collagen fiber and conglomerated into masses, and the composite resulted in severe tissue reaction after implantation. Conclusion: When mixed with a reasonable proportion of hydroxyapatite, the collagen sponge has improved structure, biodegradable performance, and biocompatibility; the composite may be a novel scaffold for tissue engineering chest wall reconstruction.

The use of recombinant activated factor VII for blood loss after cardiovascular surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To describe the early experiences with rFVIIa in the management of bleeding after cardiovascular surgery.</p><p><b>METHODS</b>From May 2006 through December 2007, 16 patients received rFVIIa during or after surgery despite conventional medical therapy and transfusion of blood products. There were 15 male patients and 1 female patients, aged from 36 to 77 years old with a mean of 52 years old. The surgical procedures include aortic procedures for 8 cases, valve replacement for 6 cases, pulmonary thromboendarterectomy for 1 case and atrial septal defect repair for 1 case. The data of these patients were reviewed and the safety and efficacy of rFVIIa after cardiovascular surgery were evaluated.</p><p><b>RESULTS</b>rFVIIa was administered as a first dose of 27.6 to 54.5 microg/kg with a mean of 40.2 microg/kg. Six patients achieved hemostasis after the first dose. Nine patients received a second administration within 30 min, with a cumulative dose of 59.3 to 90.9 microg/kg, a mean of 80.3 microg/kg. Eight patients achieved hemostasis and 1 patient went to exploration. One patient received four doses of rFVIIa with a cumulative dose of 203.4 microg/kg and the bleeding stopped. Mean amount of chest drain loss and the amount of red blood cell, fresh frozen plasma, cryoprecipitate, and platelet transfusions decreased significantly after rFVIIa administration. The total amount of chest drain losses, transfusions of red blood cell and cryoprecipitate within 12 h postoperatively was positively correlated with the time from the end of bypass to administration of rFVIIa. No thromboembolic complications and other adverse reactions were noted.</p><p><b>CONCLUSIONS</b>The use of rFVIIa is associated with reduced blood loss, rapid improvement of coagulation variables, and decreased need for blood products. rFVIIa is safe and efficacious in the management of refractory postcardiotomy bleeding.</p>

Chest wall resection and reconstruction: An update / 第二军医大学学报

Chest wall resection and reconstruction remains a severe challenge for reconstructive surgeons, which often leads to conservative treatment regimens in clinical practice, consequently resulting in poor outcomes (high morbidity and mortality). In recent 20 years, advances in muscle flap surgery and availability of chest reconstructive prosthesis have encouraged the surgeons to take an active attitude toward chest wall resection; many "unresectable" lesions now have a chance to be resected and cured. This article reviews the problems concerning the principles for chest wall resection, reconstruction, prosthesis selection, etc. in chest wall reconstruction.

Experimental study of degradable chitin long fiber reinforced polycaprolactone for reconstruction of chest wall defects / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the application of a novel degradable biomaterial as a chest wall prosthesis and provide valuable scientific basis for clinical application.</p><p><b>METHODS</b>Preparation of chitin long fiber reinforced polycaprolactone (PCL) by means of melt blending and modeling. Full-thickness chest wall defects of 10 cm x 8 cm was created in 10 dogs and then repaired with long chitin fiber reinforced PCL artificial rib in 8 dogs (tested group) and Marlex mesh in 2 dogs (control group). It was dynamically observed that the situation of the implanted chest wall prosthesis and the progress of the regeneration of the chest wall tissue postoperatively.</p><p><b>RESULTS</b>No operative and perioperative deaths were observed in all experimental dogs. In tested group, slight paradoxical respiration occurred in 2 dogs and could not be seen in 2 weeks. No chest wall subsidence and infection occurred. New bone tissue obviously regenerated around both resection ends of the ribs and integrated tightly with artificial ribs. In control group, there were evidently paradoxical respiration and chest wall subsidence. Marlex mesh folded and was enveloped by fibrous tissue.</p><p><b>CONCLUSION</b>Degradable chitin long fiber reinforced PCL can provide effective support to chest walls and is a practicable material for chest wall reconstruction.</p>